JP2563969Y2 - Hydraulic lifting equipment for tractors - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic lift device for an agricultural tractor.

[0002]

2. Description of the Related Art Agricultural tractors include a tillage depth control device for automatically controlling the tillage depth during a rotary tillage operation and a horizontal control device for holding a work posture of a work machine horizontally regardless of the inclination of the machine. There is a growing number of vehicles equipped with front wheel speed-up devices that rotate the front wheels at high speed during headland turning to minimize smooth and speedy turning and headland roughening. In the field of agricultural tractors, high performance and high quality equipped with various automatic control devices are increasing.

The above-mentioned various tractor control devices generally detect the working posture and working state of the working machine and the turning angle of the front wheels of the machine by detecting means such as a sensor and a potentiometer.
The detection signal is transmitted to a control unit composed of a microcomputer, and switching control of each control hydraulic valve is performed, thereby changing the flow path of the hydraulic oil from the hydraulic pump to operate the hydraulic cylinders provided in each part of the body. Many have a structured structure.

[0004]

However, most of the conventional devices have hydraulic valves for control which are distributed and attached to various parts of the body, so that the hydraulic piping becomes complicated and diversified, and the hydraulic piping is obstructed. As a result, there has been a problem that maintenance of each part of the aircraft becomes difficult.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and a tractor having a hydraulic case having a built-in hydraulic cylinder for vertically rotating a lift arm fixed on a transmission case. In the hydraulic lift device of the above , both sides of the hydraulic case near the rear portion
The left and right lift arms are distributed in a protruding rear
At the same time as mounting, on both sides near the front of the hydraulic case
Is the supply and discharge of oil to the hydraulic cylinder for plowing depth control
Depth control valve and horizontal control lift rod
Horizontal control valve that supplies and discharges oil to and from the cylinder
And a hydraulic cylinder for plowing depth control and a
Split valve that supplies pressurized oil to the foot rod cylinder, and others
Shunt valve that supplies pressure oil to the hydraulic cylinder
Attach it by distributing it to the left and right while shifting the position, and
Return oil from each valve passes through an oil passage formed in the hydraulic case.
The gist of the invention is that it is configured to return to the inside of the transmission case.

[0006]

According to the tractor hydraulic lift device of the present invention, each hydraulic valve is positioned on the left and right sides of the hydraulic case in the forward and backward directions.
The hydraulic pipe is easy and compact because of the structure in which the hydraulic pipes are installed in a concentrated manner while shifting , and the hydraulic pipe does not hinder the maintenance, so that the maintenance of each part of the machine body becomes easy. Each of the hydraulic valve the return fluid so <br/> to be returned to the transmission case through the hydraulic casing terms of piping for return oil is as short as possible, the efficiency in gears and bearings, etc., located in the upper portion of the transmission case Is lubricated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a transmission case (rear transmission case). A hydraulic case 3 having a built-in hydraulic cylinder S for lifting and lowering the work implement connected to a lift arm 2 is integrally fixed to an upper surface of the transmission case. This hydraulic case 3
Are equipped with tractor control hydraulic valves in a concentrated manner. That is, one side flow valve 4 and a hydraulic valve 5 for horizontal control are provided on one side surface (right side in the body traveling direction) of the hydraulic case 3, and the other side flow valve 6 and a hydraulic valve for plowing depth control are provided on the other side surface. Reference numeral 7 designates diverting valves 4 and 6 located on the front side, respectively, and the diverting valves 4 and 6 are distributed in a balanced manner to the left and right. Have been. An electromagnetic valve 10, a sequence valve 11, and a pressure reducing valve 12 are incorporated in the flow dividing valve 6, and the oil (pressure oil) of one of the hydraulic pumps 8, 9 driven by an engine (not shown). As shown in the hydraulic circuit diagram of FIG. 5, is supplied to a lift rod cylinder 13 for horizontal control and a hydraulic cylinder 14 for plowing depth control via a flow dividing valve 4. Also, the pressure oil of the other hydraulic pump 9 is normally supplied to the hydraulic cylinder 16 for the power steering device 15 through the flow dividing valve 6, but when the tractor turns, if the front wheel has a cutting angle of a predetermined angle or more, this is reduced. Upon detection, the electromagnetic valve 10 is automatically switched so that part of the pressure oil supplied to the hydraulic cylinder 16 of the power steering device 15 expands and contracts the operating cylinder 18 of the front wheel speed increasing device 17 via the electromagnetic valve 10. It has become. The diversion valve 4 has a suction port 19 and a discharge port 2
The flow dividing valve 6 has a suction port 21, a discharge port 22 to the power steering device 15, and a discharge port 23 to the front wheel speed increasing device 17. Each hydraulic valve has a tank port, and the return oil of each valve is introduced into the hydraulic case 3, and is arranged in the transmission case 1 from the hydraulic case 3 in the upper layer portion of the transmission case 1 from above. The gears and bearings (not shown) are configured to be sprinkled and returned. That is, the shunt valve 4
Is used as lubricating oil for the piston rod of the working machine elevating hydraulic cylinder S through the oil passage 3a of the hydraulic case 3 and the pipe P, and is returned to the transmission case 1 below the hydraulic case 3; Also, the return oil from the flow dividing valve 6 and the hydraulic valve 7 for controlling the plowing
Via the oil passages 3b and 3c. Therefore, the number of hydraulic pipes is as small as possible and can be shortened. The return oil from the power steering device 15 is returned to the lower part of the center case 24. H is a hydraulic hose, and 25 is a valve mounting bolt.

FIG. 3 illustrates a structure for transmitting power to the front wheels. In this case, the power to the high-speed drive gear 26 is connected and disconnected by a 2WD / 4WD switching operation lever (not shown).
In the illustrated state), when pressure oil is supplied to the cylinder 18, the cylinder 18 moves rightward in the drawing against the spring 28 of the wet-type multi-plate clutch 27 to be in “contact” with the clutch, and the fixed gear 30 of the differential pinion shaft 29. Power is transmitted to the output shaft 32 in the order of the high-speed drive gear 26, the high-speed driven gear 31, and the multi-plate clutch 27, and a pre-transport speed-up state is established (FIG. 3).
(Shown below the center of the output shaft 32). If the forward angle is less than the predetermined angle, the pressure oil is not supplied to the cylinder 18, the multi-plate clutch 27 is held in the “disconnected” state by the elastic force of the spring 28, and the fixed gear 30
→ Intermediate shaft 33 → Low speed drive gear 34 → Low speed driven gear 35 →
Power is transmitted to the output shaft 32 in the order of the steel balls 36, and
The WD state (the front and rear wheels have substantially the same peripheral speed) (the state shown above the center of the output shaft). Reference numeral 37 denotes a transmission shaft to the front wheels.

[0009]

[Effects of the Invention] As described above, the present invention provides
On both sides near the front, a valve 7 for depth control and a bar for horizontal control
While moving the lube 5, the flow dividing valves 4 and 6, respectively, back and forth
Since it is installed separately to the left and right, control oil for each part of the tractor
The pressure valve can be concentrated on both sides of the hydraulic case.
The control hydraulic valve can be changed to each part
And the hydraulic piping is used for maintenance of the aircraft.
There is no distraction and the hydraulic case 3
Make effective use of the free space of the aircraft formed on both sides
The hydraulic valve can be attached to the
Power can be compacted. Also, each valve
The return oil of 4, 6, 7 is supplied to the oil passage 3 formed in the hydraulic case 3.
a, 3b, 3c to the transmission case 1
Because it was made to return, piping for each valve 4, 6, 7
As much as possible and as short as possible
Gears and bearings located in the upper layer of the transmission case 1
Lubricating parts where lubricating oil is likely to be insufficient
It can be done efficiently using 6,7 return oil
You. Furthermore, the central part of the hydraulic case 3 is
Lifting, hydraulic pressure on transmission case 1
When assembling and disassembling the case 3, the rear part of the hydraulic case 3
For the left and right lift arms 2, 2 provided on both sides
And on both sides near the front, shifting the position back and forth
Valves 4, 5, 6, and 7 are located before and after the hydraulic case,
Improves left-right balance and good assembly / disassembly performance
There is an advantage that it is secured.

[Brief description of the drawings]

FIG. 1 is a plan view of a hydraulic case equipped with the present invention.

FIG. 2 is a cross-sectional side view of the front wheel speed increasing device.

FIG. 3 is a cross-sectional side view showing a power transmission structure to a front wheel.

FIG. 4 is a side view of the hydraulic case.

FIG. 5 is a hydraulic circuit diagram of the present invention.

FIG. 6 is a cross-sectional plan view of the hydraulic case.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transmission case 2 Lift arm 3 Hydraulic case 4 One shunt valve 5 Horizontal control valve 6 The other shunt valve 7 Plowing depth control valve 17 Front wheel speed increasing device 24 Center case

Claims (1)

(57) [Scope of request for utility model registration] 1. A tractor hydraulic lift device comprising a transmission case (1) and a hydraulic case (3) having a built-in hydraulic cylinder for vertically rotating a lift arm fixed thereto. On both sides
Is the left and right lift arms (2), (2)
Attach separately and in front of the hydraulic case (3)
Hydraulic cylinders (1
4) Till depth control valve that supplies and discharges oil to
(7) and lift rod cylinder (13) for horizontal control
Control valve for supplying / discharging oil to / from the engine (5)
And hydraulic cylinder (14) for plowing depth control, and horizontal control
For supplying pressurized oil to the lift rod cylinder (13)
Flow valve (4) and other hydraulic cylinders (16), (1
8) and a shunt valve (6) for supplying pressure oil to the front and rear
And shift it to the left or right to attach it.
Return oil from lubes (4), (6), (7) is hydraulic case
The oil passages (3a), (3b) and (3c) formed in (3)
A hydraulic lift device for a tractor, wherein the hydraulic lift device is configured to return to the inside of the transmission case (1) via the transmission.